Controlling the humidity in greenhouses can reduce pests and diseases

Solar greenhouses are a high-temperature and high-humidity environment. If the high temperature and high humidity last for a long time, not only will the growth of plants in the greenhouse be affected, but it will also easily induce a variety of pests and diseases, which will lead to a decline in product quality and reduced economic benefits.

Due to the poor control capabilities of solar greenhouses and plastic greenhouses, it is necessary to strengthen the management of the greenhouse and control the temperature and humidity inside the greenhouse. There are several methods for controlling the temperature and humidity of solar greenhouses and greenhouses:

1. Reasonable irrigation. Different types of crops have different growth periods and require different amounts of water. Therefore, it is necessary to use water reasonably and strictly control the amount of water to avoid flooding. Use sub-film irrigation. If conditions permit, use drip irrigation. Since drip irrigation can directly infiltrate water into the root zone of crops, it can carry fertilizer with water, so that water and fertilizer can be fully utilized, avoiding the loss of water and fertilizer caused by flooding. It can save 60% of water, 50% of fertilizer, reduce the use of pesticides by 60%, and increase production by more than 15%.

2. Covering the entire greenhouse with plastic film Covering the cultivation area, walkways, ditches, etc. in the greenhouse with plastic film to prevent moisture evaporation from increasing the humidity in the greenhouse, while increasing the amount of sunlight entering, significantly increasing the greenhouse temperature and ground temperature, achieving the purpose of preventing and curing diseases.

3. Using fog-eliminating and drip-free film In addition to the functions of ordinary drip-free film, this film also has the ability to absorb moisture in the surrounding air and form a water flow along the greenhouse film, preventing and eliminating fog in the greenhouse and reducing air humidity. This film reduces humidity by 10% to 12% compared to ordinary drip-free film, increases light intensity by 20% to 25%, and increases the greenhouse ground temperature and air temperature by 2 to 3°C, reducing the occurrence of diseases and insect pests.

4. Covering the ground with chopped grass Spread 5 to 6 cm thick wheat bran and chopped straw in the large row furrows of the greenhouse. This practice not only reduces the evaporation of surface water and avoids excessive humidity in the greenhouse, but also has the functions of inhibiting the growth and spread of weeds, increasing temperature, releasing carbon dioxide, etc., and can also be used as organic fertilizer for the next crop.

5. Use of aerosols and dusts Aerosols and dusts are pesticides that can prevent the occurrence of pests and diseases. Commonly used pesticides in production include chlorothalonil, prochlorperazine, chloramphenicol, chlorfenapyr, chlorfenapyr, chlorfenapyr, and chlorfenapyr. They can prevent and control blight, downy mildew, gray mold, sclerotinia, and anthrax.

6. Ventilation to dissipate moisture and keep warm When the humidity in the greenhouse is too high, ventilation can be used to reduce the humidity. Generally, the greenhouse temperature is controlled at 25-30℃ during the day. If it exceeds 30℃, the skylight should be opened to let in air, ventilate and remove moisture, and replenish carbon dioxide content. If the temperature exceeds 35℃ at noon on a sunny day, the ventilation time around noon should be extended and the ventilation openings should be gradually increased. That is, the skylight should be opened to let in air, and the front window should be opened to let in air, so that the greenhouse temperature is kept at 28-30℃ and the relative humidity is within 60%. The greenhouse temperature at night should not be lower than 12-18℃.

7. Increase temperature, light and humidity. The heat in the greenhouse comes from solar energy. If the light is good, the temperature in the greenhouse is high, the relative humidity of the air is reduced, and pests and diseases are reduced, which is beneficial to the growth and development of plants and enhances their disease resistance. The main measures to increase temperature and light in the greenhouse include: choosing a reasonable greenhouse structure, using fog-eliminating and drip-free film, promptly removing the covering, keeping the greenhouse film clean, reasonable layout, strengthening plant adjustment, hanging reflective curtains, artificial lighting, promoting double-film covering-free straw mat technology, and using film pressing line film pressing technology.